diff --git a/src/widgets/widgets/qscrollarea.cpp b/src/widgets/widgets/qscrollarea.cpp
index f7a4f8e446..f880240ea7 100644
--- a/src/widgets/widgets/qscrollarea.cpp
+++ b/src/widgets/widgets/qscrollarea.cpp
@@ -196,7 +196,20 @@ void QScrollAreaPrivate::updateScrollBars()
     if (resizable) {
         if ((widget->layout() ? widget->layout()->hasHeightForWidth() : widget->sizePolicy().hasHeightForWidth())) {
             QSize p_hfw = p.expandedTo(min).boundedTo(max);
-            int h = widget->heightForWidth( p_hfw.width() );
+            int h = widget->heightForWidth(p_hfw.width());
+            // If the height we calculated requires a vertical scrollbar,
+            // then we need to constrain the width and calculate the height again,
+            // otherwise we end up flipping the scrollbar on and off all the time.
+            if (vbarpolicy == Qt::ScrollBarAsNeeded) {
+                int vbarWidth = vbar->sizeHint().width();
+                QSize m_hfw = m.expandedTo(min).boundedTo(max);
+                while (h > m.height() && vbarWidth) {
+                    --vbarWidth;
+                    --m_hfw.rwidth();
+                    h = widget->heightForWidth(m_hfw.width());
+                }
+                max = QSize(m_hfw.width(), qMax(m_hfw.height(), h));
+            }
             min = QSize(p_hfw.width(), qMax(p_hfw.height(), h));
         }
     }
diff --git a/tests/auto/widgets/widgets/qscrollarea/tst_qscrollarea.cpp b/tests/auto/widgets/widgets/qscrollarea/tst_qscrollarea.cpp
index 8a9200f406..e0fd42e95c 100644
--- a/tests/auto/widgets/widgets/qscrollarea/tst_qscrollarea.cpp
+++ b/tests/auto/widgets/widgets/qscrollarea/tst_qscrollarea.cpp
@@ -33,6 +33,7 @@
 #include <qdebug.h>
 #include <qscrollarea.h>
 #include <qlayout.h>
+#include <qscrollbar.h>
 
 class tst_QScrollArea : public QObject
 {
@@ -46,6 +47,7 @@ private slots:
     void getSetCheck();
     void ensureMicroFocusVisible_Task_167838();
     void checkHFW_Task_197736();
+    void stableHeightForWidth();
 };
 
 tst_QScrollArea::tst_QScrollArea()
@@ -165,5 +167,61 @@ void tst_QScrollArea::checkHFW_Task_197736()
     QCOMPARE(w->height(), 200);
 }
 
+
+/*
+    If the scroll area rides the size where, due to the height-for-width
+    implementation of the widget, the vertical scrollbar is needed only
+    if the vertical scrollbar is visible, then we don't want it to flip
+    back and forth, but rather constrain the width of the widget.
+    See QTBUG-92958.
+*/
+void tst_QScrollArea::stableHeightForWidth()
+{
+    struct HeightForWidthWidget : public QWidget
+    {
+        HeightForWidthWidget()
+        {
+            QSizePolicy policy = sizePolicy();
+            policy.setHeightForWidth(true);
+            setSizePolicy(policy);
+        }
+        // Aspect ratio 1:1
+        int heightForWidth(int width) const override { return width; }
+    };
+
+    class HeightForWidthArea : public QScrollArea
+    {
+    public:
+        HeightForWidthArea()
+        {
+            this->verticalScrollBar()->installEventFilter(this);
+        }
+    protected:
+        bool eventFilter(QObject *obj, QEvent *e) override
+        {
+            if (obj == verticalScrollBar() && e->type() == QEvent::Hide)
+                ++m_hideCount;
+            return QScrollArea::eventFilter(obj,e);
+        }
+    public:
+        int m_hideCount = 0;
+    };
+
+    HeightForWidthArea area;
+    HeightForWidthWidget equalWHWidget;
+    area.setWidget(&equalWHWidget);
+    area.setWidgetResizable(true);
+    // at this size, the widget wants to be 501 pixels high,
+    // requiring a vertical scrollbar in a 499 pixel high area.
+    // but the width resulting from showing the scrollbar would
+    // be less than 499, so no scrollbars would be needed anymore.
+    area.resize(501, 499);
+    area.show();
+    QTest::qWait(500);
+    // if the scrollbar got hidden more than once, then the layout
+    // isn't stable.
+    QVERIFY(area.m_hideCount <= 1);
+}
+
 QTEST_MAIN(tst_QScrollArea)
 #include "tst_qscrollarea.moc"